/*
*
* Template Numerical Toolkit (TNT)
*
* Mathematical and Computational Sciences Division
* National Institute of Technology,
* Gaithersburg, MD USA
*
*
* This software was developed at the National Institute of Standards and
* Technology (NIST) by employees of the Federal Government in the course
* of their official duties. Pursuant to title 17 Section 105 of the
* United States Code, this software is not subject to copyright protection
* and is in the public domain. NIST assumes no responsibility whatsoever for
* its use by other parties, and makes no guarantees, expressed or implied,
* about its quality, reliability, or any other characteristic.
*
*/



#ifndef TNT_ARRAY2D_H
#define TNT_ARRAY2D_H

#include <cstdlib>
#include <iostream>
#ifdef TNT_BOUNDS_CHECK
#include <assert.h>
#endif

#include "tnt_array1d.h"

namespace TNT
{

  template <class T>
  class Array2D
  {


  private:



    Array1D<T> data_;
    Array1D<T*> v_;
    int m_;
    int n_;

  public:

    typedef         T   value_type;
    Array2D();
    Array2D(int m, int n);
    Array2D(int m, int n,  T *a);
    Array2D(int m, int n, const T &a);
    inline Array2D(const Array2D &A);
    inline operator T**();
    inline operator const T**();
    inline Array2D & operator=(const T &a);
    inline Array2D & operator=(const Array2D &A);
    inline Array2D & ref(const Array2D &A);
    Array2D copy() const;
    Array2D & inject(const Array2D & A);
    inline T* operator[](int i);
    inline const T* operator[](int i) const;
    inline int dim1() const;
    inline int dim2() const;
    ~Array2D();

    /* extended interface (not part of the standard) */


    inline int ref_count();
    inline int ref_count_data();
    inline int ref_count_dim1();
    Array2D subarray(int i0, int i1, int j0, int j1);

  };


  template <class T>
  Array2D<T>::Array2D() : data_(), v_(), m_(0), n_(0) {}

  template <class T>
  Array2D<T>::Array2D(const Array2D<T> &A) : data_(A.data_), v_(A.v_),
  m_(A.m_), n_(A.n_) {}




  template <class T>
  Array2D<T>::Array2D(int m, int n) : data_(m*n), v_(m), m_(m), n_(n)
  {
    if (m>0 && n>0)
    {
      T* p = &(data_[0]);
      for (int i=0; i<m; i++)
      {
        v_[i] = p;
        p += n;
      }
    }
  }



  template <class T>
  Array2D<T>::Array2D(int m, int n, const T &val) : data_(m*n), v_(m),
      m_(m), n_(n)
  {
    if (m>0 && n>0)
    {
      data_ = val;
      T* p  = &(data_[0]);
      for (int i=0; i<m; i++)
      {
        v_[i] = p;
        p += n;
      }
    }
  }

  template <class T>
  Array2D<T>::Array2D(int m, int n, T *a) : data_(m*n, a), v_(m), m_(m), n_(n)
  {
    if (m>0 && n>0)
    {
      T* p = &(data_[0]);

      for (int i=0; i<m; i++)
      {
        v_[i] = p;
        p += n;
      }
    }
  }


  template <class T>
  inline T* Array2D<T>::operator[](int i)
  {
#ifdef TNT_BOUNDS_CHECK
    assert(i >= 0);
    assert(i < m_);
#endif

    return v_[i];

  }


  template <class T>
  inline const T* Array2D<T>::operator[](int i) const
  {
#ifdef TNT_BOUNDS_CHECK
    assert(i >= 0);
    assert(i < m_);
#endif

    return v_[i];

  }

  template <class T>
  Array2D<T> & Array2D<T>::operator=(const T &a)
  {
    /* non-optimzied, but will work with subarrays in future verions */

    for (int i=0; i<m_; i++)
      for (int j=0; j<n_; j++)
        v_[i][j] = a;
    return *this;
  }




  template <class T>
  Array2D<T> Array2D<T>::copy() const
  {
    Array2D A(m_, n_);

    for (int i=0; i<m_; i++)
      for (int j=0; j<n_; j++)
        A[i][j] = v_[i][j];


    return A;
  }


  template <class T>
  Array2D<T> & Array2D<T>::inject(const Array2D &A)
  {
    if (A.m_ == m_ &&  A.n_ == n_)
    {
      for (int i=0; i<m_; i++)
        for (int j=0; j<n_; j++)
          v_[i][j] = A[i][j];
    }
    return *this;
  }




  template <class T>
  Array2D<T> & Array2D<T>::ref(const Array2D<T> &A)
  {
    if (this != &A)
    {
      v_ = A.v_;
      data_ = A.data_;
      m_ = A.m_;
      n_ = A.n_;

    }
    return *this;
  }



  template <class T>
  Array2D<T> & Array2D<T>::operator=(const Array2D<T> &A)
  {
    return ref(A);
  }

  template <class T>
  inline int Array2D<T>::dim1() const { return m_; }

  template <class T>
  inline int Array2D<T>::dim2() const { return n_; }


  template <class T>
  Array2D<T>::~Array2D() {}




  template <class T>
  inline Array2D<T>::operator T**()
  {
    return &(v_[0]);
  }
  template <class T>
  inline Array2D<T>::operator const T**()
  {
    return &(v_[0]);
  }

  /* ............... extended interface ............... */
  /**
  	Create a new view to a subarray defined by the boundaries
  	[i0][i0] and [i1][j1].  The size of the subarray is
  	(i1-i0) by (j1-j0).  If either of these lengths are zero
  	or negative, the subarray view is null.

  */
  template <class T>
  Array2D<T> Array2D<T>::subarray(int i0, int i1, int j0, int j1)
  {
    Array2D<T> A;
    int m = i1-i0+1;
    int n = j1-j0+1;

    /* if either length is zero or negative, this is an invalide
    	subarray. return a null view.
    */
    if (m<1 || n<1)
      return A;

    A.data_ = data_;
    A.m_ = m;
    A.n_ = n;
    A.v_ = Array1D<T*>(m);
    T* p = &(data_[0]) + i0 *  n_ + j0;
    for (int i=0; i<m; i++)
    {
      A.v_[i] = p + i*n_;

    }
    return A;
  }

  template <class T>
  inline int Array2D<T>::ref_count()
  {
    return ref_count_data();
  }



  template <class T>
  inline int Array2D<T>::ref_count_data()
  {
    return data_.ref_count();
  }

  template <class T>
  inline int Array2D<T>::ref_count_dim1()
  {
    return v_.ref_count();
  }




} /* namespace TNT */

#endif
/* TNT_ARRAY2D_H */

